Safety device for elevators.



S. H'. MILLER. SAFETY DEVICE FOR ELEVATORS.

APPLICATION FILED APR. 29. 1915.

1,197,529. Patented Sept. 5,1916.

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SAMUEL H. MILLER, OF LAT-ROBE, PENNSYLVANIA.

SAFETY DEVICE FOR ELEVATORS.

Specification of Letters Patent.

Patented Sept. 5, rate.

Application filed April 29, 1915. Serial No. 24,700.

To all whom it may concern:

Be it known that I, SAMUEL H. MILLER a citizen of the United States,residing at Latrobe, \Vestmoreland county, Pennsylvania, have invented anew and useful Safety Device for Elevators, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings, forming part of this specification, in whichFigure 1 isa side elevation of one form of my safety device shown inconnection with an elevator. Fig. 2 is a diagram illustrating one set ofsafety cables. Fig. 3 is a detail sectional view of one form of the stopactuating mechanism. Fig. 4- is a detail sectional view of one of thesafety cable sheaves.-

Fig. 5 is a plan view of the mechanism shown in Fig. 1. Fig. 6 is adetail sectional view on the line VTVI' of Fig. 5. Fig. 6 is a detailsectional view illustrating the sliding frame 16 and its guys. Fig. 7 isa plan view of a modified form of mechanism. Fig. 8 is a front view ofthe stop or safety device actuating mechanism shown in Fig. 7, and Fig.9 is a detail side elevation of the lifting cable sheaves and the stopmechanism actuating sheave of the device shown in Figs. 7 and 8.

This invention relates to safety devices for hoists, and is designed toprovide a simple and effective safety or stop device in connection witha safety cable connected to the load, and in which there is provided asuitable device for stopping the movement of the load if the hoistingcable should part or should become unduly slack.

The object of my invention is to provide a device of this characterwhich is controlled by means of a stop under the control of the liftingcable. 1

The precise nature of my invention will be best understood by referenceto the accompanying drawings, which will now be de scribed, it beingpremised, however, that various changes may be made in the details ofconstruction and arrangement of the parts without departing from thespirit and scope of my invention, as defined in the appended claims.

Referring to Figs. 1 to 6 of the drawings, the reference character 2designates the usual side rails forming the guides for a car 3. In theconstruction shown in the drawings, I have provided two sets of safetycables, there being one set oneach side ofthe car and elevator shaft,and as one set is a duplicate of the other, I will only describe the seton one side. 4' and P are sheaves rotatably mounted at the top of theshaft, and 5 and 5 are similar sheaves at the bottom of the shaft, thesheaves 4 and 5 being at the front of the shaft, while the sheaves dand5* are at the back of the shaft. Loosely mounted on a shaft 6 at the topof the elevator shaft and at approximately the center thereof aresheaves 7 and 7 and 8 and 8 are sheaves loosely mounted on a shaft 9 atthe bottom of the shaft. 10 is a safety cable connected to the top ofthe car 2, and passes around the sheaves 7, 4, 5 and 8, the other endbeing connectedto the bottom of the car, and 10 is a similar cableconnected to the car in the same manner and which passes over-sheaves 74+, 5 andS. The cables and sheaves are so arranged that when the car 2is moving upwardly the sheave 7 will ro tate in one direction, while thesheave 7 rotates in the reverse direction, and when the car movesdownwardly the sheaves 7 and 7- will rotate in reverse directions fromthat in which they rotate when the car is moving upwardly. The safetycables make approximately a turn and a, quarter about their respectivesheaves 7 and 7, to prevent the cables slipping over these sheaves, asherein after described; but only make approximately a quarter of aturnaround the other sheaves.

The shaft 6 is slidably mounted in suit able bearings in the supportingframework, the sheave 7 being held inposition on the shaft by means ofcollars 11 so that this sheave will be moved laterally when the shaft 6is moved in a longitudinal direction. The sheave 7 is not directlymounted on the shaft 6, but rotates on a sleeve 12 surrounding the shaft6. These sheaves 7 and 7 are provided with clutching projections 13 and13 respectively, and are arranged to stop the movement of the sheaves7and 7 a when moved into clutching engagement, as hereinafter described.Pivotally connected to a suitable bracket 14: connected to thesupporting structure is a bell crank 15, one end thereof being connectedto the shaft 6, while the other end is connected to a sliding frame 16mounted in guides 17 connected to the sheave supporting structure.

18 is the usual lifting cable connected to the top of the car, and.which passes over tile a sheave 19 at the top of the shaft, then over asmall sheave 20 connected to the slidingframe 16, a sheave 21 on one endof a lever 22, and thence around the usual sheave 23 at the bottom ofthe shaft to the hoisting drum. The lever 22 is mounted in a bracket 24connected to the supporting framework, the end opposite the sheave 7engaging the sliding frame 16. The arrangement is such that when theload is on the lifting cable the parts will be held in the positionsshown in the drawings, so that the sheaves 7 and 7 are free to rotate.Surrounding the shaft 6 and engaging the framework and the bell crank 15is a spring 25 which tends to move the shaft 6, together with the sheave7, to bring its clutching members in engagement with the clutchingmembers on the sheave 7 If, for any reason, the lifting cable shouldpart or should become unduly slack, the spring 25 will immediately bringthe sheaves 7 and 7 a into clutching engagement and stop the movement ofthe sheaves, together with the safety cables and the car.

As the operating mechanism for the shaft 6 on one side is a duplicate ofthat on the other, it will not be necessary to describe both of them, itbeing understood, however, that when the safety cables on one side ofthe shaft are stopped by means of the clutch device the cables on theother side will be simultaneously stopped by a similar device.

When it is desired to repair any of the parts, or adjust them, it isonly necessary to lower the car onto its usual supporting springs at thebottom of the shaft, which will permit the stopping apparatus to bethrown into action, and at the same time relieve all strain on thesafety cables, so that any of the parts can readily be adjusted orrepaired.

In Figs. 7, 8 and 9 I have shown a modified form which is very similarto that shown in the figures already described, and in which I h aveused the same reference characters, with the letter b affixed. In thisconstruction, the parts are the same, with the exception that theactuating bell cranks 15 are arranged to swing about pivots at rightangles to those shown in the other figures. In this case the liftingcable passes over sheaves 26 and under a sheave 27 rotatably mounted ona shaft connected to the bell cranks 15".

I have shown and described two safety cables for checking the movementof the the load and arranged to be moved thereby,

sheaves for said cable, a shaft for the sheave,

a lifting cable connected to the load, a stop member on one of thesafety cable sheaves, a second stop member arranged to coact with thestop member on the sheave to lock the sheave against rotation, one ofsaid stop members being arranged to move relative to the other in a lineparallel to the shaft and a stop actuating device controlled by thelifting cable and arranged to cause one stop member to move into lockingengagement with the other stop member; substantially as described.

2. A safety device for elevators, comprising a safety cable connected tothe car at both ends and arranged to be moved thereby, a sheave overwhich the cable passes, a clutch member connected to the sheave of thesafety cable, a second clutch device adapted to coact therewith, alifting cable connected to the car, and a clutch actuating devicecontrolled by the lifting cable and adapted to move one of the clutchmembers relative to the other to stop the movement of the safety cablesheave; substantially as described.

3. A safety device for elevators, comprising a plurality of safetycables connected to the car at both ends and arranged to be movedthereby, there being one of said cables on each side of the car, sheavesfor each of said cables, a clutch device connected to one of the sheavesof each of said cables, a second clutch device on one side of each ofsaid sheaves and adapted to coact with the clutch members on the safetycable sheaves, a lifting cable connected to the car, a clutch actuatingmechanism controlled by the lifting cable and arranged to move theclutching devices of the safety cables toward each other to stop-thesheaves if the lifting cable parts or becomes unduly slack;substantially as described.

4:. A safety device for elevators, comprising a plurality of safetycables connected to the car, a sheave for each of said cables, saidsheaves and cables being so arranged that the sheaves will rotate inreverse directions, a clutch device on each of said sheaves adapted tobe brought into engagement with each other, a lifting cable connected tothe car, and a clutch actuating device controlled by the lifting cable,substantially as described.

5. A safety device for elevators, comprising a plurality of safetycables on each side of the elevator shaft connected to the car andarranged to be moved thereby, a lifting cable connected to the car, asheave for each of the safety cables, the sheaves for the cables on eachside of the car being arranged to rotate in reverse directions, clutchdevices on each of said sheaves, lever mechanism for moving one sheaveof each set laterally relative to the other sheave, said lever mechanismincluding a sliding frame, springs for moving said sheaves toward eachother, and an actuating device connected to the lever mechanismcontrolled by the safety cable for holding the clutch devices on thesheaves out of engagement With each other, sub stantially as described.

In testimony whereof, I have hereunto set my hand.

SAMUEL H. MILLER.

Witnesses:

JESSE B. HELLER, H. M. CORWIN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner ofi Patents, Washington, D. G.

